Various types of mounting brackets have been constructed in the past to support heater coils within an electric heater or clothes dryer. In such brackets, the heater coils pass through ceramic grommets or other types of insulating bushings retained in brackets and then the brackets are mounted on a retaining wall. Such brackets attempted to provide a simple, efficient and cost effective way of securing the insulating bushings and for mounting the coils to the retaining wall.
It must be appreciated that to be cost efficient, the mounting bracket should be simple to construct and should be capable of being quickly secured and released without special tools. In this respect, attempts in the prior art to provide such a mounting bracket met with varying degrees of success.
For example, Canadian patent No. 771,787 of Kinney issued Nov. 14, 1967 describes a mounting assembly to be inserted into a pipe encasement. The assembly includes special ceramic insulators having a dove-tail base that is retained in a mounting strip and secured by means of jaws or clips that are then spot welded onto the mounting strip. This mounting assembly requires a special ceramic insulator and several interacting pieces as well as a welding step during installation.
Canadian patent No. 889,457 of Fox issued Dec. 28, 1971 describes a mounting assembly consisting of a series of lanced tabs bent out of the reflector pan or support wall of the dryer. Insulator bushings are mounted on these tabs by means of a resilient clip which are held in place by a tongue in the clip that locks into an aperture in the bent out tab. This requires a unique type of insulator bushing and an intricately formed clip.
Canadian patent No. 1,017,786 of Wightman et al issued Sept. 20, 1977 discloses a rather complicated and relatively expensive means for securing a heater coil to a specially designed insulator. The insulator is held to a support structure by means of a projection that extends through an aperture in the insulator. A metal clip holds the heating coil onto the insulator.
U.S. Pat. No. 4,656,340 of the present inventor issued Apr. 7, 1987 discloses a bracket plate which is bent along its longitudinal axis to form a U-shaped support for a pair of insulator bushings. The support and bushings are secured into position by cooperating tabs that project from the heater wall. While this mounting is an improvement in the art, in that a single support plate is used to secure the bushings, it requires several complicated manipulative steps. The simplification of the steps required for carrying out the present invention will be described below. These reduce the manufacturing and repair costs of the dryer or heater.
U.S. Pat. No. 3,967,094 of Petersen et al issued June 29, 1976 discloses a support member for insulator bushings. Two cooperating strips having cut-outs for seating the bushings are positioned in lapping relationship so that the folded edge of one strip is locked in engagement with the folded edge of the other. One inherent limitation of this design is that all the bushings are lined up in side by side or parallel relationship, since each end of a strip is secured to a side wall of the heater frame. This allows only an up and down arrangement of the heater coil. It would not permit the arrangement of heater coils along the parameter of a drum such as is required in a clothes dryer.